A hearing aid or instrument may be a purely acoustic device or an electro-acoustic device configured to amplify sounds for the user. Hearing aids are suitable for persons having some degree of hearing loss. For example, persons having a normal degree of hearing loss may be associated with the inability to detect sounds between −10 to 15 decibels (dB). On the other hand, slight hearing loss may be associated with the inability to detect sounds between 16 to 25 dB, mild hearing loss may be associated with the inability to detect sounds between 26 to 40 dB, moderate hearing loss may be associated with the inability to detect sounds between 41 to 55 dB, moderately severe hearing loss may be associated with the inability to detect sounds between 56 to 70 dB, severe hearing loss may be associated with the inability to detect sounds between 71 to 90 dB, and profound hearing loss may be associated with the inability to detect sounds greater than 91 dB.